I'm currently working on an interface that provides connection by bluetooth to a serial device by the help of a bluetooth RS232 adapter. I already implemented bluetooth chat example and achieved that I get ascii strings sent by the serial device to my smartphone. However to update that serial device I would

a) need a possibility to send a *.exe file (OBEX not possible due to profile boundary of the adapter)

or

b) send the hex files content to the serial device. However I'm not totally sure if reading hex files works similar to other files or if I have to think about special circumstances.

So my question for now. Anybody familiar with reading hex files and sending the full content to another device? I would appreciate some ideas, thoughts about that. Even better would be a tutorial I know there are some concerning reading and writing files but I'm not 100% sure they are working for my kind of issue. This most likely because the software of the serial device checks incoming files and parses the hex content to overwrite already existing files in the memory.